package com.hmdp.utils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWoker {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWoker (StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1704067200;

    /**
     * 序列号长度
     */
    private static final int COUNT_BITS = 32;

    public long nextId (String keyPrefix) {
        //1. 获取时间戳
        LocalDateTime now = LocalDateTime.now();
        long newSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timeStamp = newSecond - BEGIN_TIMESTAMP;

        //2. 生成序列号
        // 2.1 获取日期
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        // 2.2  自增长
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //3. 拼接
        return timeStamp << COUNT_BITS | count;
    }
}
